145 research outputs found
Deciphering cassava brown streak virus infection in cassava through VPg mediated host protein interactions
No full textCassava brown streak disease (CBSD) poses a major threat to cassava production in Africa. Identifying cassava proteins that interact with cassava brown streak virus (CBSV), the major causal virus, can help elucidate the mechanisms of infection and resistance. Here we constructed a cassava cDNA library and screened for proteins interacting with CBSV viral genome-linked protein (VPg) using yeast two-hybrid assays, identifying 36 interactors. Four candidates were validated in Nicotiana benthamiana via bimolecular fluorescence complementation. Functional categories included chloroplast proteins, ribosomal components, chaperones, metabolic enzymes, and defence-related proteins. In prior RNA-seq datasets from CBSV or UCBSV-inoculated cassava, comprising the susceptible variety Albert and the resistant variety Namikonga, 16 VPg-interacting genes were identified among the differentially expressed genes (|log₂FC| > 1), with 2 detected in Albert and 15 in Namikonga. These results indicate that VPg-interacting host proteins are involved in CBSV infection dynamics and also explaining the differential responses of resistant and susceptible cassava varieties, thus offering potential new molecular targets for CBSD management.
Sumesh M. Kakkunnath , Sophie Bouvaine, Siji P. Kavil1, and M. N. Maruthi
Mechanistic Aspects of the Polymerization of Lactide Using a Highly Efficient Aluminum(III) Catalytic System
No full textbibtex: ISI:000400802300037 bibtex\location:'1155 16TH ST, NW, WASHINGTON, DC 20036 USA',publisher:'AMER CHEMICAL SOC',type:'Article',affiliation:'Thomas, CM (Reprint Author), PSL Res Univ, Chim ParisTech, CNRS, Inst Rech Chim Paris, F-75005 Paris, France. Maron, L (Reprint Author), Univ Toulouse, 135 Ave Rangueil, F-31077 Toulouse, France. Maron, L (Reprint Author), UPS, INSA, 135 Ave Rangueil, F-31077 Toulouse, France. Maron, L (Reprint Author), IRSAMC, LPCNO, 135 Ave Rangueil, F-31077 Toulouse, France. Maron, L (Reprint Author), CNRS, F-31077 Toulouse, France. Maron, L (Reprint Author), IRSAMC, UMR 5215, F-31077 Toulouse, France. Robert, Carine; Schmid, Thibault E.; Richard, Vincent; Haquette, Pierre; Raman, Sumesh K.; Rager, Marie-Noelle; Thomas, Christophe M., PSL Res Univ, Chim ParisTech, CNRS, Inst Rech Chim Paris, F-75005 Paris, France. Gauvin, Regis M.; Morin, Yohann, Univ Lille, Univ Artois, CNRS, Cent Lille,ENSCL,UCCS,UMR 8181, F-59000 Lille, France. Trivelli, Xavier, Univ Lille, CNRS, UGSF, UMR 8576, F-59000 Lille, France. Guerineau, Vincent, Univ Paris Sud, Univ Paris Saclay, CNRS UPR2301, Inst Chim Subst Nat, Ave Terrasse, F-91198 Gif Sur Yvette, France. del Rosal, Iker; Maron, Laurent, Univ Toulouse, 135 Ave Rangueil, F-31077 Toulouse, France. del Rosal, Iker; Maron, Laurent, UPS, INSA, 135 Ave Rangueil, F-31077 Toulouse, France. del Rosal, Iker; Maron, Laurent, IRSAMC, LPCNO, 135 Ave Rangueil, F-31077 Toulouse, France. del Rosal, Iker; Maron, Laurent, CNRS, F-31077 Toulouse, France. del Rosal, Iker; Maron, Laurent, IRSAMC, UMR 5215, F-31077 Toulouse, France.','author-email':'[email protected] [email protected]',da:'2018-12-05','doc-delivery-number':'EU1SV','funding-acknowledgement':'ENSCP; ANR [ANR-10-PDOC-010-01]; Fondation Pierre-Gilles de Gennes; CNRS; CALMIP-EOS [p0833]; CNRS [TGIR-RMN-THC Fr3050]','funding-text':'ENSCP, ANR (grant ANR-10-PDOC-010-01), Fondation Pierre-Gilles de Gennes, and CNRS are thanked for financial support of this work. This work was performed using HPC resources from CALMIP-EOS (grant p0833). We would like to thank Purac for a generous loan of rac-lactide. C.M.T. is grateful to the Institut Universitaire de France (IUF). Financial support from the TGIR-RMN-THC Fr3050 CNRS for conducting the research is gratefully acknowledged.','journal-iso':'J. Am. Chem. Soc.','keywords-plus':'RING-OPENING POLYMERIZATION; CHROMIUM SALEN COMPLEXES; QUATERNARY ORGANIC SALT; CARBON-DIOXIDE; PROPYLENE-OXIDE; RAC-LACTIDE; STEREOSELECTIVE POLYMERIZATION; ALTERNATING COPOLYMERIZATION; CYCLIC CARBONATES; RACEMIC LACTIDE','number-of-cited-references':'85','orcid-numbers':'Del Rosal, Iker/0000-0001-6898-4550 Gauvin, Regis/0000-0002-4788-4363 Guerineau, Vincent/0000-0002-1747-5016 Thomas, Christophe/0000-0001-8014-4255','research-areas':'Chemistry','researcherid-numbers':'Del Rosal, Iker/H-3419-2012','times-cited':'12','unique-id':'ISI:000400802300037','usage-count-last-180-days':'13','usage-count-since-2013':'83','web-of-science-categories':'Chemistry, Multidisciplinary'\International audienceWe report here a unique example of an in situ generated aluminum initiator stabilized by a C-2-symmetric salen ligand which shows a hitherto unknown high activity for the ROP of rac-lactide at room temperature. Using a simple and robust catalyst system, which is prepared from a salen complex and an onium salt, this convenient route employs readily available reagents that afford polylactide in good yields with narrow polydispersity indices, without the need for time-consuming and expensive processes that are typically required for catalyst preparation and purification. In line with the experimental evidence, DFT studies reveal that initiation and propagation proceed via an external alkoxide attack on the coordinated monomer
Studies on Performance Enhancement of Infrared and Terahertz Detectors for Space Applications
Get PDFCurrently, the concept of multipurpose spacecrafts is being transformed into many small spacecrafts each of them performing specific tasks and thus leading to the realization of pico and nano satellites. No matter what is the application or size, demand for more number of IR channels for earth observation is ever increasing which necessitates significant reduction in the mass, power requirement and cost of the IR detectors. In this scenario, several order of magnitude mass and power savings associated with uncooled IR arrays are advantageous compared to cooled photon detectors. However the poor speed of response of uncooled microbolometer array devices obstruct the total replacement of cooled detectors in thermal imaging applications. This is especially true when the mission requires 50 m to 100 m ground resolution, in which even the "fastest" micro bolometer arrays turns "too slow" to follow the ground trace when looked from low earth orbit (LEO). Hence there is a great and unfulfilled requirement of faster uncooled detector arrays for meeting the demand for future micro and mini satellite projects for advanced missions. The present thesis describes the systematic studies carried out in development of high performance IR and THz detectors for space applications.
Ge-Si-O thin films are prepared by ion beam sputtering technique with argon (Ar) alone and argon and oxygen as sputtering species, using sputtering targets of different compositions of Ge and SiO2. The deposited thin films are amorphous in nature and have chemical compositions close to that of the target. The study of electrical properties has shown that the activation energy and hence the thermistor constant (β) and electrical resistivity (ρ) are sensitive to oxygen flow rate, and they are the least for thin films prepared with Ar alone as the sputtering species. Different thermal isolation structures (TIS), consisting of silicon nitride (Si3N4) membrane of different thicknesses, Ge-Si-O thin film and, chromium coating on the rear side of the membrane, are prepared by bulk micro-machining technique, whose thermal conductance (Gth) properties are evaluated from the experimentally determined current-voltage (I-V) characteristics. Gth shows non-linear dependence with respect to raise in temperature of thin film thermistor due to Joule heating. The infrared micro-bolometer detectors, fabricated using one of the TIS structures have shown responsivity (<v) close to 115 V W−1 at a bias voltage of 1.5 V and chopping frequency of 10 Hz, thermal time constant (τth) of 2.5 ms and noise voltage of 255 nV Hz−1⁄2 against the corresponding thermal properties of Gth and thermal capacitance Cth equal to 9.0 × 10−5 W K−1 and 1.95 × 10−7 J K−1 respectively. The detectors are found to have uniform spectral response in the infrared region from 2 µm to 20 µm, and NEDT in the range from 108 mK to 574 mK when used with an F/1 optical system. The detector, in an infrared earth sensor system, is tested before an extended black body which simulates the earth disc in the laboratory and the results are discussed.
As an extension of the single element detector to array device, design of a microbolometer array for earth sensor dispensing of scanning mechanisms is presented. It makes use of four microbolometer arrays with in-line staggered configuration that stare at the earth horizons, perceiving IR radiation in the spectral band of 14 µm to 16 µm. Design of the microbolometer has been carried out keeping in mind low power, lightweight, without compromising on the performance. An array configuration of 16 × 2 pixels is designed and developed for this purpose. Finite elemental analysis is carried out for design optimization to yield best thermal properties and thus high performance of the detectors. Suitable optical design configuration was arrived to image the earth horizon on to array. Using this optimum design, prototype arrays have been fabricated, packaged and tested in front of the black body radiation source and found to have Responsivity, NEP, and D∗ of 120 V W−1, 5.0 W Hz−1⁄2, 1.10 × 107 cm Hz1⁄2 W−1 respectively. The pixels show a uniform response within a spread of ±6 % and the pixel resistances are within a range of ±5 %.
Optically Immersed Bolometer IR detectors are fabricated using electron beam evaporated Vanadium Oxide as the sensing material. Spin coated polyimide is used as medium to optically immerse the sensing element to the flat surface of a hemispherical germanium lens. This optical immersion layer also serves as the thermal impedance control layer and decides the performance of the devices in terms of responsivity and noise parameters. The devices have been packaged in suitable electro-optical packages and the detector parameters are studied in detail. Thermal time constant varies from 0.57 ms to 6.1 ms and responsivity from 75VW−1 to 757VW−1 corresponding to polyimide thickness in the range 2.0 μm to 70 μm for a detector bias of 9V. Highest D obtained was 1.28 × 108 cm Hz1⁄2W−1. Noise Equivalent Temperature Difference (NETD) of 20mK is achieved for devices with polyimide thickness of 32 μm, whereas the NETD × th product is the lowest for devices with moderate thickness of thermal impedance layer.
Bolometric THz detectors were fabricated using V2O5 as sensing element immersed
onto germanium hemispherical lens using polyimide as immersion media. These
detectors were characterized for their efficiency in detection of THz radiation in
the range 10 THz to 35 THz emitted by a black body radiator. The responsivity of
the devices determined in four different frequency bands covering the spectrum of
interest and a maximum responsivity of 398VW−1 was observed. A variation in the
responsivity is observed which is due to the characteristics absorption of polyimide
in the THz region of interest and can be avoided by replacing with HDPE which
has less attenuation. NEP of 6.8 × 10−10WHz−1⁄2 was observed which is very close
to the state of art in the case of uncooled detectors which entitles the detectors for
spectroscopic applications. Specific Detectivity D* was observed to be much higher
than the conventional detectors thanks to the benefits of immersion. NETD of 26mK
was observed which is advantageous of application of these detectors in imaging
applications
These studies have lead to development of a new technology for fabrication of high
performance IR and THz detectors which can be used for spectroscopic and imaging
applications. Further, this technology can be scaled for development of linear and area
arrays finding applications where the speed of respnose as well as sensitivity are of
equal importance. from 0.57 ms to 6.1 ms and responsivity from 75 V W−1 to 757 V W−1 corresponding to polyimide thickness in the range 2.0 µm to 70 µm for a detector bias of 9 V. Highest D∗ obtained was 1.28 × 108 cm Hz1⁄2 W−1. Noise Equivalent Temperature Difference (NETD) of 20 mK is achieved for devices with polyimide thickness of 32 µm, whereas the NETD × τth product is the lowest for devices with moderate thickness of thermal impedance layer.
Bolometric THz detectors were fabricated using V2O5 as sensing element immersed onto germanium hemispherical lens using polyimide as immersion media. These detectors were characterized for their efficiency in detection of THz radiation in the range 10 THz to 35 THz emitted by a black body radiator. The responsivity of the devices determined in four different frequency bands covering the spectrum of interest and a maximum responsivity of 398 V W−1 was observed. A variation in the responsivity is observed which is due to the characteristics absorption of polyimide in the THz region of interest and can be avoided by replacing with HDPE which has less attenuation. NEP of 6.8 × 10−10 W Hz−1⁄2 was observed which is very close to the state of art in the case of uncooled detectors which entitles the detectors for spectroscopic applications. Specific Detectivity D* was observed to be much higher than the conventional detectors thanks to the benefits of immersion. NETD of 26 mK was observed which is advantageous of application of these detectors in imaging applications
These studies have lead to development of a new technology for fabrication of high performance IR and THz detectors which can be used for spectroscopic and imaging applications. Further, this technology can be scaled for development of linear and area arrays finding applications where the speed of respnose as well as sensitivity are of equal importance
Investigations On The Effect Of Process Parameters On The Composition Of DC Magnetron Sputter Deposited NiTi Shape Memory Alloy Thin Films
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Copolymérisation monoxyde de carbone/hétérocycle : nouveaux catalyseurs et nouveaux polymères biodégradables
No full textCertains polymères synthétiques biodégradables ont montré des propriétés physico-chimiques aussi intéressantes que celles des plastiques issus du pétrole. Cependant, leur coût élevé dû au prix des matières premières ainsi qu’au faible nombre de voies de synthèse efficaces empêchent leur rentabilité. Une des alternatives serait le développement de méthodes de production viables économiquement par l’utilisation de catalyseurs productifs et de voies de synthèses à économie d’atomes. Ce manuscrit rassemble les travaux effectués durant la thèse sur une série de catalyseurs organométalliques hautement actifs pour la synthèse du poly(lactide), de nouvelles stratégies catalytiques pour la production du poly(3-hydroxybutyrate) et la polymérisation à économie d’atomes d’α-aminoacide-N-carboxyanhydrides pour la production de poly(α-peptides).Many synthetic biodegradable polymers show competitive physical properties compared to petrochemically derived plastics. However, due to the low availability and high cost of renewable feed stocks or lack of efficient synthetic routes, their industrial production and successful commercial execution lacks economical feasibility. One way to improve the current situation is the implementation of cost efficient methods either by using productive catalysts or by atom-efficient synthetic methods. Here we report the discovery of a series of highly active organometallic catalysts for the synthesis of poly(lactide), new catalytic methodologies for the production of poly(3-hydroxybutyrate), and an atom-efficient polymerization of α-aminoacid-N-carboxyanhydrides to poly(α-peptides)
Strain hardening behaviour in forming of sintered iron-0.35% carbon powder metallurgy preform during cold upsetting
No full textA complete experimental investigation on the instantaneous strain-hardening behaviour of powder metallurgy preforms of Fe-0.35%C was carried out. The strain hardening behaviour of the above-mentioned P/M sintered steel preforms with aspect ratio of 0.4 and 0.6, respectively, under triaxial stress state condition was determined by cold upsetting under nil/no and graphite lubricant conditions. The instantaneous strain hardening value (n i), strength coefficient (Ki), and the stress as a function of strain and densification were obtained and analyzed. Further, a relation is obtained from a semi-log plot of stress against relative density. This was analyzed to study the hardening behaviour due to the densification as applied stress is a function of induced strain as well as of densification in the powder metallurgy materials
Mississippi Renewable Energy and Energy Efficiency Report. A snap shot of related activities in the state of Mississippi
No full textPersistence with golimumab in immune-mediated rheumatic diseases: a systematic review of real-world evidence in rheumatoid arthritis, axial spondyloarthritis, and psoriatic arthritis
No full textAxel Svedbom,1 Chiara Storck,2 Sumesh Kachroo,3 Marinella Govoni,4 Ahmed Khalifa5 1Real World Strategy and Analytics, Mapi Group, Stockholm, Sweden; 2Real World Strategy and Analytics, Mapi Group, Munich, Germany; 3Center for Observational and Real-World Evidence (CORE), Merck & Co, Kenilworth, NJ, USA; 4MSD Italy, Rome, Italy; 5Medical Affairs Immunology, MSD Switzerland, Luzern, Switzerland Purpose: In immune-mediated rheumatic diseases (IMRDs), persistence to treatment may be used as a surrogate marker for long-term treatment success. In previous comparisons of persistence to tumor necrosis factor α inhibitors (TNFis), a paucity of data for subcutaneous (SC) golimumab was identified. The aim of this study was to conduct a systematic review of persistence to SC golimumab in clinical practice and contextualize these data with five-year persistence estimates from long-term open-label extension (OLE) trials of SC TNFis in IMRDs.Patients and methods: PubMed, Embase, MEDLINE, and conference proceedings from European League Against Rheumatism (EULAR), American College of Rheumatology (ACR), and International Society for Pharmacoeconomics and Outcomes Research (ISPOR) were searched. All studies on patients treated with SC golimumab for IMRD were included if they reported data on the persistence to golimumab.Results: Of 376 available references identified through the searches, 12 studies with a total of 4,910 patients met the inclusion criteria. Furthermore, nine OLE trials were available. Among the included studies from clinical practice, at six months, one year, two years, and three years, the proportion of patients persistent to treatment ranged from 63% to 91%, 47% to 80%, 40% to 77%, and 32% to 67%, respectively. In the four studies that included comparisons to other biologics, golimumab was either statistically noninferior or statistically superior to other treatments, an observation that was supported by indirect comparisons of unadjusted point estimates of OLE trials.Conclusion: The data reviewed in this study indicate that golimumab may have higher persistence than other TNFis, a notion that is supported by indirect comparisons of persistence data from OLEs of randomized controlled trials (RCTs). Furthermore, the study suggests that persistence may be lower in biologic-experienced compared with biologic-naive patients and higher in axial spondyloarthritis compared with rheumatoid arthritis and psoriatic arthritis. Keywords: golimumab, Simponi, Treatment persistence, drug survival, retention rates, real-world evidence (RWE
Dynamic load balancing for petascale quantum Monte Carlo applications: The Alias method
Get PDFDiffusion Monte Carlo is a highly accurate Quantum Monte Carlo method for electronic structure calculations of materials, but it requires frequent load balancing or population redistribution steps to maintain efficiency on parallel machines. This step can be a significant factor affecting performance, and will become more important as the number of processing elements increases. We propose a new dynamic load balancing algorithm, the Alias Method, and evaluate it theoretically and empirically. An important feature of the new algorithm is that the load can be perfectly balanced with each process receiving at most one message. It is also optimal in the maximum size of messages received by any process. We also optimize its implementation to reduce network contention, a process facilitated by the low messaging requirement of the algorithm: a simple renumbering of the MPI ranks based on proximity and a space filling curve significantly improves the MPI Allgather performance. Empirical results on the petaflop Cray XT Jaguar supercomputer at ORNL show up to 30% improvement in performance on 120,000 cores. The load balancing algorithm may be straightforwardly implemented in existing codes. The algorithm may also be employed by any method with many near identical computational tasks that require load balancing.Journal ArticlePublishe
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